| Message ID | 20190110005117.18282-1-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/mmu_notifier: mm/rmap.c: Fix a mmu_notifier range bug in try_to_unmap_one | expand |
On Wed, Jan 09, 2019 at 04:51:17PM -0800, Sean Christopherson wrote: > The conversion to use a structure for mmu_notifier_invalidate_range_*() > unintentionally changed the usage in try_to_unmap_one() to init the > 'struct mmu_notifier_range' with vma->vm_start instead of @address, > i.e. it invalidates the wrong address range. Revert to the correct > address range. > > Manifests as KVM use-after-free WARNINGs and subsequent "BUG: Bad page > state in process X" errors when reclaiming from a KVM guest due to KVM > removing the wrong pages from its own mappings. > > Reported-by: leozinho29_eu@hotmail.com > Reported-by: Mike Galbraith <efault@gmx.de> > Reported-by: Adam Borowski <kilobyte@angband.pl> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> > Cc: Christian König <christian.koenig@amd.com> > Cc: Jan Kara <jack@suse.cz> > Cc: Matthew Wilcox <mawilcox@microsoft.com> > Cc: Ross Zwisler <zwisler@kernel.org> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Radim Krčmář <rkrcmar@redhat.com> > Cc: Michal Hocko <mhocko@kernel.org> > Cc: Felix Kuehling <felix.kuehling@amd.com> > Cc: Ralph Campbell <rcampbell@nvidia.com> > Cc: John Hubbard <jhubbard@nvidia.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2") > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > > FWIW, I looked through all other calls to mmu_notifier_range_init() in > the patch and didn't spot any other unintentional functional changes. > > mm/rmap.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/rmap.c b/mm/rmap.c > index 68a1a5b869a5..0454ecc29537 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -1371,8 +1371,8 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, > * Note that the page can not be free in this function as call of > * try_to_unmap() must hold a reference on the page. > */ > - mmu_notifier_range_init(&range, vma->vm_mm, vma->vm_start, > - min(vma->vm_end, vma->vm_start + > + mmu_notifier_range_init(&range, vma->vm_mm, address, > + min(vma->vm_end, address + > (PAGE_SIZE << compound_order(page)))); > if (PageHuge(page)) { > /* > -- > 2.19.2 >
> The conversion to use a structure for mmu_notifier_invalidate_range_*() > unintentionally changed the usage in try_to_unmap_one() to init the > 'struct mmu_notifier_range' with vma->vm_start instead of @address, > i.e. it invalidates the wrong address range. Revert to the correct > address range. > > Manifests as KVM use-after-free WARNINGs and subsequent "BUG: Bad page > state in process X" errors when reclaiming from a KVM guest due to KVM > removing the wrong pages from its own mappings. > > Reported-by: leozinho29_eu@hotmail.com > Reported-by: Mike Galbraith <efault@gmx.de> > Reported-by: Adam Borowski <kilobyte@angband.pl> > Cc: Jérôme Glisse <jglisse@redhat.com> > Cc: Christian König <christian.koenig@amd.com> > Cc: Jan Kara <jack@suse.cz> > Cc: Matthew Wilcox <mawilcox@microsoft.com> > Cc: Ross Zwisler <zwisler@kernel.org> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Radim Krčmář <rkrcmar@redhat.com> > Cc: Michal Hocko <mhocko@kernel.org> > Cc: Felix Kuehling <felix.kuehling@amd.com> > Cc: Ralph Campbell <rcampbell@nvidia.com> > Cc: John Hubbard <jhubbard@nvidia.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for > invalidate_range_start/end calls v2") > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > > FWIW, I looked through all other calls to mmu_notifier_range_init() in > the patch and didn't spot any other unintentional functional changes. > > mm/rmap.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/rmap.c b/mm/rmap.c > index 68a1a5b869a5..0454ecc29537 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -1371,8 +1371,8 @@ static bool try_to_unmap_one(struct page *page, struct > vm_area_struct *vma, > * Note that the page can not be free in this function as call of > * try_to_unmap() must hold a reference on the page. > */ > - mmu_notifier_range_init(&range, vma->vm_mm, vma->vm_start, > - min(vma->vm_end, vma->vm_start + > + mmu_notifier_range_init(&range, vma->vm_mm, address, > + min(vma->vm_end, address + > (PAGE_SIZE << compound_order(page)))); > if (PageHuge(page)) { > /* > -- I was suspecting this patch for some other issue. But could not spot this after in depth analyzing the changed "invalidate_range_start/end calls". Its indeed a good catch. Reviewed-by: Pankaj gupta <pagupta@redhat.com> > 2.19.2 > >
On Wed, Jan 09, 2019 at 04:51:17PM -0800, Sean Christopherson wrote: > Manifests as KVM use-after-free WARNINGs and subsequent "BUG: Bad page > state in process X" errors when reclaiming from a KVM guest due to KVM > removing the wrong pages from its own mappings. With your patch, no badness happened so far. Thanks! > Reported-by: Adam Borowski <kilobyte@angband.pl> > Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2") > --- a/mm/rmap.c > +++ b/mm/rmap.c > - mmu_notifier_range_init(&range, vma->vm_mm, vma->vm_start, > - min(vma->vm_end, vma->vm_start + > + mmu_notifier_range_init(&range, vma->vm_mm, address, > + min(vma->vm_end, address + Meow.
After applying this patch, I'm no longer seeing dmesg messages with WARNINGs and BUGs, and both host and guests are stable. Thank you. Às 22:51 de 09/01/2019, Sean Christopherson escreveu: > The conversion to use a structure for mmu_notifier_invalidate_range_*() > unintentionally changed the usage in try_to_unmap_one() to init the > 'struct mmu_notifier_range' with vma->vm_start instead of @address, > i.e. it invalidates the wrong address range. Revert to the correct > address range. > > Manifests as KVM use-after-free WARNINGs and subsequent "BUG: Bad page > state in process X" errors when reclaiming from a KVM guest due to KVM > removing the wrong pages from its own mappings. > > Reported-by: leozinho29_eu@hotmail.com > Reported-by: Mike Galbraith <efault@gmx.de> > Reported-by: Adam Borowski <kilobyte@angband.pl> > Cc: Jérôme Glisse <jglisse@redhat.com> > Cc: Christian König <christian.koenig@amd.com> > Cc: Jan Kara <jack@suse.cz> > Cc: Matthew Wilcox <mawilcox@microsoft.com> > Cc: Ross Zwisler <zwisler@kernel.org> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Radim Krčmář <rkrcmar@redhat.com> > Cc: Michal Hocko <mhocko@kernel.org> > Cc: Felix Kuehling <felix.kuehling@amd.com> > Cc: Ralph Campbell <rcampbell@nvidia.com> > Cc: John Hubbard <jhubbard@nvidia.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2") > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > > FWIW, I looked through all other calls to mmu_notifier_range_init() in > the patch and didn't spot any other unintentional functional changes. > > mm/rmap.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/rmap.c b/mm/rmap.c > index 68a1a5b869a5..0454ecc29537 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -1371,8 +1371,8 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, > * Note that the page can not be free in this function as call of > * try_to_unmap() must hold a reference on the page. > */ > - mmu_notifier_range_init(&range, vma->vm_mm, vma->vm_start, > - min(vma->vm_end, vma->vm_start + > + mmu_notifier_range_init(&range, vma->vm_mm, address, > + min(vma->vm_end, address + > (PAGE_SIZE << compound_order(page)))); > if (PageHuge(page)) { > /* >
diff --git a/mm/rmap.c b/mm/rmap.c index 68a1a5b869a5..0454ecc29537 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1371,8 +1371,8 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, * Note that the page can not be free in this function as call of * try_to_unmap() must hold a reference on the page. */ - mmu_notifier_range_init(&range, vma->vm_mm, vma->vm_start, - min(vma->vm_end, vma->vm_start + + mmu_notifier_range_init(&range, vma->vm_mm, address, + min(vma->vm_end, address + (PAGE_SIZE << compound_order(page)))); if (PageHuge(page)) { /*
The conversion to use a structure for mmu_notifier_invalidate_range_*() unintentionally changed the usage in try_to_unmap_one() to init the 'struct mmu_notifier_range' with vma->vm_start instead of @address, i.e. it invalidates the wrong address range. Revert to the correct address range. Manifests as KVM use-after-free WARNINGs and subsequent "BUG: Bad page state in process X" errors when reclaiming from a KVM guest due to KVM removing the wrong pages from its own mappings. Reported-by: leozinho29_eu@hotmail.com Reported-by: Mike Galbraith <efault@gmx.de> Reported-by: Adam Borowski <kilobyte@angband.pl> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Christian König <christian.koenig@amd.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- FWIW, I looked through all other calls to mmu_notifier_range_init() in the patch and didn't spot any other unintentional functional changes. mm/rmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)